US Patent 6965166 Semiconductor device of chip-on-chip structure

A semiconductor device including a first semiconductor chip, a second semiconductor chip bonded to the first semiconductor chip in a stacked relation, and a registration structure which causes the first and second semiconductor chips to be positioned with respect to each other by depression-projection engagement therebetween. The registration structure includes, for example, a registration recess provided on a surface of the first semiconductor chip, and a registration projection provided on a surface of the second semiconductor chip for engagement with the registration recess. The registration projection may be a spherical member provided on the surface of the second semiconductor chip.